The present invention relates to a granulating apparatus, especially for strands of thermoplastic materials. The strands of thermoplastic materials emerge, still in a molten condition, from nozzles and into a transporting means provided with cooling water, which transports the strands to a cutting device, such as a cutting roller.
An apparatus of this type is known from French Patent Publication No. 2,133,666. In the known apparatus, the still molten strands are supplied from above into a transport chute in such a manner that the chute intercepts the strands, whereby the latter are bent. Thus, the transport chute forms, so to speak, a support for the strands which deflects the latter from a substantially vertical direction into a substantially horizontal direction. At the end of the transport chute there is arranged a cutting mechanism. In the known apparatus it is necessary to carefully adjust the operational speed of the cutting mechanism relative to the supply speed of the strands, because due to the type of guiding provided for the strands, the pull exerted on the strands by the cutting mechanism tends to lift the strands off the bottom of the transport chute. Thus, the strands are lifted out of the cooling water, whereby the desired cooling effect is undesirably avoided. On the other hand, it is not desirable to supply the strands to the cutting mechanism at a too low speed because that would result in a jamming ahead or upstream of the cutting mechanism, whereby the strands would tend to follow a wavy path, and might thus come into contact with each other which is undesirable, since the consistency of the strands is still rather tacky, whereby the strands might stick to each other. Thus, the cutting mechanism must be constructed in such a manner that it is capable of receiving the strands in a manner which adapts itself automatically to the supply speed of the strands. The supply speed of the strands may vary considerably depending on the varying viscosity.
According to German Patent Publication No. 2,230,187 it is known to deflect the strands from a feed advance device comprising a pair of revolving conveyor bands by means of tilted baffle plates, which are sprayed with water, said deflection taking place in response to any trouble that might occur in the normal feed advance of the strands by the pair of revolving conveyor bands. Thus, in this prior art granulating apparatus for strands of thermoplastic material, said baffle plates become effective at any time when it is not desired to supply strands to the regular feed advance mechanism. No teaching can be taken from this reference with regard to the use of rigid transport chutes for interconnecting the nozzles and the feeding mechanism.